In each case, Kaczynski and cohorts dug up something damning about the nominee or appointee. And in each case, it wasn’t some dark secret or sinister conspiracy from long ago.

It was their own words.

Kaczynski’s four-member group — known as KFile after its 28-year-old founder — may be the foremost practitioner of the journalistic equivalent of dumpster diving. Their reportorial MO is simple, if tedious: They dig through social-media posts, old audio and video recordings and forgotten speeches, articles and books to find troubling comments uttered or written by the people they’re investigating.

KFile didn’t pioneer this archaeological approach (political campaigns on the left and right have been doing “opposition research” for decades). But in the social-media age, it can be a highly effective journalistic technique. Virtually everyone who has ever tweeted or posted to Facebook or Instagram has laid a digital trail that can be followed by anyone with some time and a lot of patience.

These days, the art of exhuming offensive statements is not just focused on political figures. Showbiz and sports figures are called out as well: Brewers pitcher Josh Hader, among others, was recently found to have fired off offensive tweets years ago. Some purists may consider the technique more of a “gotcha” hit than enlightening journalism, but it seems here to stay.

In Higbie’s case, KFile came up with a trove of Internet radio programs hosted by the former Navy SEAL and conservative media personality in 2013 and 2014. The recordings captured Higbie disparaging African Americans, Muslims, women, gay men and others. In one instance, he suggested gun owners should be permitted to shoot immigrants at the border. He also asserted that 75 percent of veterans with PTSD “don’t actually have it” and are “milking something for a little extra money in disability or they’re just . . . lying.”

After KFile’s exposé in January, Higbie quit as chief of external affairs for the federal agency that oversees AmeriCorps and other volunteer-service programs. “I’m sorry,” he tweeted afterward.“Those words do not reflect who I am or what I stand for, I regret saying them.”

Higbie, now the host of a podcast, added in an interview: “Kaczynski is a reporter with an agenda. I won’t take away from his due diligence, but he clearly has the same agenda as CNN. They’re ­anti-Trump.” Kaczynski says KFile did extensive vetting of Hillary Clinton and Bernie Sanders during the 2016 campaign, and while his team has focused on Trump appointees and Republicans since the 2016 election, he says he has looked into Democrats, too. He’s just found less outrageous stuff. Example: Rep. Elijah Cummings (D-Md.) saying on a radio show that Hillary Clinton would be impeached if she had done some of the things Trump has.

KFile found instances in which other Trump appointees made racist comments (Jamie Johnson) and anti-gay slurs (Bauserman, Mateer); promoted the “birther” conspiracy and said crude things about President Barack Obama (Bradford and Todd Johnson); or floated bizarre theories (Hartnett White, Trump’s pick for a top environmental post, had once likened scientific evidence of global warming to “a kind of paganism”). It found multiple instances of plagiarism in books and academic work by Crowley and Clarke.

The CNN team’s track record raises a couple of questions: Why have Kaczynski and his young colleagues (editor Kyle Blaine, 27, and researcher-reporters Chris Massie, 26, and Nathan McDermott, 30) proved better at vetting Trump’s nominees than the people in the federal government who are supposed to be vetting Trump’s nominees? And why are there so many people with questionable records knocking around Trump’s administration in the first place?

“A lot of the people who joined Trump’s campaign weren’t the usual operatives, especially very early in the campaign,” answers Kaczynski, at work in CNN’s office in New York. When Trump won, “there were thousands of positions to fill, and not that many people willing to work for him. They got people from the fringes. I don’t think there was a lot of vetting.”

The most promising trails typically emerged from those who had been bloggers or radio hosts before joining the administration.

One such appointee, a White House senior adviser at the Department of Homeland Security named Frank Wuco, had been a radio host in Florida and a frequent guest on other radio programs. Jackpot: Recordings revealed that Wuco had been an enthusiastic purveyor of far-right conspiracy theories, such as the false claims that former CIA director John Brennan had converted to Islam and that Obama’s attorney general, Eric H. Holder Jr., had been a member of the radical Black Panthers group in the 1970s. KFile posted the sound clips of Wuco’s comments in December. Unlike many of KFile’s targets, Wuco retained his job.

Kaczynski, who grew up in Cleveland’s suburbs, was a news and politics geek from an early age. His father, Stephen, an lawyer (now retired), watched countless hours of cable news, and his son absorbed the habit.

He made his first splash as an Internet deep diver in 2011, when he was a 21-year-old student at St. John’s University in Queens.

While rummaging through some online videos, he found one of David Weprin, the Democratic candidate for Anthony Weiner’s vacated congressional seat, awkwardly dancing at an outdoor music festival in Brooklyn. Kaczynski put the clip on his YouTube channel and tipped off a few journalists, such as Ben Smith, then at Politico. A few news outlets wrote up the find, which was more comical and embarrassing than scandalous.

Weprin went on to lose narrowly to Republican Bob Turner. (Kaczynski later served as an intern for Turner but said he had no connection to Turner’s campaign when he found the Weprin video.)

Thereafter, Kaczynski started rooting around C-SPAN’s archives, unearthing curious clips, such as one of Mitt Romney as a Massachusetts gubernatorial candidate in 2002 in which Romney promised voters that he holds “progressive” views. At the time (2012) Romney was telling Republican primary voters that he was the most conservative choice for president.

Kaczynski’s scoops earned him invitations from CNN, C-SPAN and MSNBC to talk about his emerging specialty. He also drew the attention of Smith, the new editor of BuzzFeed. Smith offered Kaczynski a job at BuzzFeed; Kaczynski accepted, dropping out of St. John’s before his senior year. He never finished his degree.

Kaczynski, right, and members of his CNN team, known as KFile, at the network’s offices in New York City, (Jon Sarlin/CNN)

Smith — who has called Kaczynski “a self-made genius” — seemed to know what he had. He created a team to support Kaczynski, eventually putting him together with two interns, McDermott and Massie. Blaine became their editor.

Their biggest “get” was an audio recording that rebutted candidate Donald Trump’s repeated assertions that he had opposed the U.S. invasion of Iraq before the war began in 2003. The KFilers sorted through 50 hours of “Howard Stern Show” recordings to find a clip of Stern asking Trump in 2002 if he was in favor of invading Iraq. “Yeah, I guess so,” Trump responded then. “I wish the first time it was done correctly.”

Just before the election in October 2016, CNN lured not just Kaczynski away from BuzzFeed, but all of his bandmates. They spend most of their days in monkish toil, with occasional breaks for Nintendo 64 games. “We learned very quickly that you can’t listen to hundreds of hours of Roy Moore speeches and do nothing else without going crazy,” said McDermott.

One of Kaczynski’s stories at CNN quickly spun out of control last summer. After Trump retweeted an GIF of him that had been altered to show him body-slamming and punching a person with the CNN logo superimposed over his face, KFile tracked down the anonymous individual who had created the meme. They found that the person, a Reddit user, had a history of posting anti-Semitic, racist and Islamophobic comments.

Kaczynski wrote in his story that CNN wasn’t publishing the user’s name “because he is a private citizen who has issued an extensive statement of apology, showed his remorse by saying he has taken down all his offending posts, and because he said he is not going to repeat this ugly behavior on social media again.” The story added, “CNN reserves the right to publish his identity should any of that change.”

The last sentence kicked up an uproar. Right-wing provocateurs began to accuse CNN of threatening to expose the anonymous meme-maker unless he behaved according to CNN’s wishes. Soon the hashtag #CNNblackmail began trending on Twitter.

All four KFile members were subjected to threats and insults. Kaczynski got hit hardest. He received so many death threats that he and his wife had to leave their home and live in a hotel for a week, accompanied by CNN security. People posted the home addresses of his parents, sister, brother and mother-in-law. Even his parents received death threats.

Kaczynski says the offending line — added by “an executive” at CNN, whom he won’t identify — was “misinterpreted, and I understand why it was misinterpreted. It was read in a totally different way than it was meant.”

With the midterm elections approaching, KFile has shifted its attention to the candidates.

One of the unlucky recipients of the team’s recent attention has been Rep. Jason Lewis, a first-term Republican from Minnesota who is locked in a tight race for his seat. Before winning election in 2016, Lewis used to have — yes — a radio show on which he said some, well, provocative things. Kaczynski acquired five months of audio files from the show, which aired from 2009 to 2014, from a former deputy chair of the Republican Party of Minnesota.

Lewis defended his comments as “rhetorical” in nature in a local radio interview. “I was paid to be provocative,” he declared.

Kaczynski vows that he and his team will keep mining the public record for more instances of outrage, hypocrisy and extremism involving candidates of both parties. “We’re doing literally any race — congressional, Senate, gubernatorial,” he said.

Given KFile’s record of digging up words some may have thought were buried and forgotten, the candidates might consider that a warning.

Paul FarhiPaul Farhi is The Washington Post's media reporter. He started at The Post in 1988 and has been a financial reporter, a political reporter and a Style reporter. Follow